Check engine light

[Sprock]

Hi all , bought a 2002 3.0 Patrol wagon 4 months ago , intermittently the check engine light comes of with varying degrees of power loss , goes great for 2-3 weeks then plays up , when it's going well it flies but when it plays up it barely pulls its own weight along , no rhyme or reason to it - rough rds or freeway . Have replaced MAF sensor , cleaned ALL earth leads , removed battery leads for a few hrs , changed 3 fuel filters - 1st 1 had a tiny bit of water in it but last 2 fine . Put scan tool on & brings up P7 fuel injection feedback . Local fuel injection mob want to put a pump on it but I'm not convinced & at $3000 I want to be sure . Im told a few different things will bring up that fault code ? Any help welcome as I'm close to burning the thing .

[Avo]

one of my mates had a problem with no power and gutless on his,it ended up being a fuel sensor somewhere on it..700-800 bucks I think he said...goes like a shower of shit no....hopefully someone who knows a bit more will chime in soon..i'll ring him later and try and find out for sure

[Sprock]

Thanks mate , the intermittent thing has got me , if the pump is that stuffed it'll barely pull itself along - I can't imagine it'd come good for weeks & go like a shower of shit . I believe the pump 'talks' to the crank sensor , so maybe that sensor is crook ? & im told the 'PNP' switch ( whatever that is ) on the gearbox can play up & give the same symptoms I've got ? They tell me the gearbox sensor is under $50 so I'll get 1 tomora & I'll look into the crank sensor price aswell , been a process of elimination so far ...

[Rumcajs]

These are usually results of fuel starvation/air in the fuel/bad fuel. So long you have none of those then it is the pump and eventually it will give up on you.

If you can monitor/observe ICV% via ECUTalk interface/software (worth every cent) when it goes pear shaped you can then check for air in fuel for example.

There is no easy fix if it is internal electronics problem and Bosch/Zexel VP44 IP is well know for these failures. The trouble is that sensors are not exactly easily replaceable and most Diesel Injection specialists are encouraged to change over the pump as it is much simpler for them. If you can find specialist willing to check/strip and fix the unfixable (broken pump controller PCB connections) you will still pay handsomely.

My take is unless you are desperate you can source change over pump from Baileys Diesel group for around $2,000, trouble is you still need to fit it which is the headache too.

If you are going to fit replacement pump consider fitting external lift pump as well.

PN (park/neutral switch) is another symptom but doesn't generate Injection pump code and usually manifest itself with trouble getting it revved up past certain RPM.

Easily checked by starting the engine and hitting heat/fast idle switch, RPMs should raise to 1,100, selecting a gear should drop them back to low idle (750 RPM)as you move the lever from Neutral.

Regards

[Avo]

read through this sprock
http://www.nissanpatrol.com.au/forums/showthread.php?23679-ZD30-Engine-Challenge-Intermittent-Power-Loss
hope it helps

[Sprock]

Thanks Rumcajs , yeah it idles up with heat switch on but cuts back when put it into drive so I assume it's not that then 😩 , thanks WA489 , just read that 5 mins ago - I've been trawling the forum for anything remotely related to my problem . IF the pump is the problem has anyone heard of them playing up as bad as mine but then coming good for a few weeks then playing up again for a day or so & so on & so on ?

[Rumcajs]

Yes they can play up for a while.

Anyway you need to eliminate the possibilities and then decide. Methodical approach is required.

See diagnostic procedures bellow:

[Sprock]

Thank for that , hope it's not the pump but we'll see - if it gets to that it'll be a job for someone else , I don't have the time or patience to pull it apart but mainly the time factor . Thanks again - more process of elimination tomorrow- fit clear fuel lines to check for bubbles , replace ALL rubber fuel lines etc . I've had top of tank open ( see earlier thread 'fuel tank issue ) . Tank was spotless however found the metal tray that should be spot welded in the bottom was moving around as much as the spring loaded pickup would allow, removed it from tank as I couldn't weld it in there & didn't see its purpose - I'm told it's a holder for a submersible pump in the petrol Patrols ? . Intermittent problem still persisted 😤

[threedogs]

@ RUMCAJS I have Yendors ECU-Talk and the icv% is around 75% most the time,
However I notice when I go away its high when the tanks are full and gets down
to 55% on the way home when tanks are low.
By doing that lift pump mod are you masking a problem???

[Sprock]

By lift pump do you mean the primer on top of the filter housing or a seperate unit down near the tank to pressurise the system ?

[threedogs]

By lift pump do you mean the primer on top of the filter housing or a seperate unit down near the tank to pressurise the system ?

You use a seperate carter pump about 48 lpm I think

[Sprock]

Just found Fletchs' post about lift pump . I'll try that . If the Injector pumps' the problem that won't solve it will it ? Changed ECU relay this mornin - check light still on but no loss of power at this stage but that fluctuates every other time anyway . Will disconnect batteries again now that I've played around with a few things & see if it goes away . Not confident but we'll see .

[threedogs]

You mean the ECM relays dont you,
you can swap with the air-con just for test purposes

[Rumcajs]

@ RUMCAJS I have Yendors ECU-Talk and the icv% is around 75% most the time,
However I notice when I go away its high when the tanks are full and gets down
to 55% on the way home when tanks are low.
By doing that lift pump mod are you masking a problem???

Nope, you are not masking a problem with a additional lift pump, indeed you are helping the system big time and best news; also brings improvement to low down torque as well.

Bosch designed the injection pump to work with additional lift pump (VP44 has internal lift pump to cope with certain fuel flow) but left it up to vendors/manufacturers to implement , most don't as that means extra money to spent and we all know how vehicle manufacturers design their vehicles: bare minimum and cheapest!

Once under full load the internal lift pump barely copes on its own especially at lower revs range when fuel is used not only for power but for lubrication, cooling and hydraulic timing operation. Ever wondered why ZD30 Di is such a slug at take off, watch the ICV% as it drops bellow 50% it needs to go higher for fuel timing advance, essentially a drop in the pressure and volume causes the injection timing to retard hence a poor performance on take offs.

Bosch radial injection pumps are terrible design and nightmare for customers full stop. This lunacy finally stopped when "common rail" was reinvented again.....

Regards


Just found Fletchs' post about lift pump . I'll try that . If the Injector pumps' the problem that won't solve it will it ? Changed ECU relay this mornin - check light still on but no loss of power at this stage but that fluctuates every other time anyway . Will disconnect batteries again now that I've played around with a few things & see if it goes away . Not confident but we'll see .

Not really if the pump is already knackered but since you are well advised to fit lift pump for a new/replacement IP what have you got to loose by trying the lift pump first.
Having positive pressure on the suction line might show other problem which is the cause (leak)

Just don't forget you will have to carry out "injector leak off line fuel return mod" before fitting the lift pump otherwise you'll pump the sump full of diesel in no time.....

Regards

[Sprock]

Thanks all for your input , yeah 3dogs the ECM relays - that's what I've always called them but someone referred to them as 'ECU' relays so I thought Nissan terminology was different to Cummins like I'm used to . Swapped A/C relay with ECM & went for a drive & engine light came on but no power loss - sometimes it takes a while other times power loss is instant . Disconnected batteries while I removed intercooler & pipes to check & clean , fair bit of oily gunge around the sides of intake pipe directly above EGR pipe but nowhere as bad as some of the pics I've seen. Ran out of time to pull manifold off but cleaned down in there as far as I could with a bent screwdriver & rags . Took it for a squirt for 20mins & touch wood NO LIGHT came on , I'm not confident as I haven't really changed anything apart from ECM relay , however optimistically hopeful it helped & disconnecting batteries reset ECM .
Thanks Rumcajs - Fletchs' post about lift pump clearly states ( & shows ) the spill line mod . I'll try that as like you say I've got nothing to lose .

[Sprock]

Hey my catch can arrived - it's poor quality plastic thing & the lid doesn't screw on properly , it does however have a stainless mesh filter . It was $100 & now I see on EBay there's allot catch cans for half that price but don't look to have a filter - do they need 1 or can someone give me direction to a decent catch can ?

[Avo]

Mudski is a vendor here look up northern4x4 on ebay mate..send him a pm here and he'll look after you

[Sprock]

Thanks mate 👍🏼